// guard.sol -- simple whitelist implementation of DSAuthority

// Copyright (C) 2017  DappHub, LLC

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity >=0.4.23;

import "ds-auth/auth.sol";

contract DSGuardEvents {
    event LogPermit(
        bytes32 indexed src,
        bytes32 indexed dst,
        bytes32 indexed sig
    );

    event LogForbid(
        bytes32 indexed src,
        bytes32 indexed dst,
        bytes32 indexed sig
    );
}

contract DSGuard is DSAuth, DSAuthority, DSGuardEvents {
    bytes32 constant public ANY = bytes32(uint(-1));

    mapping (bytes32 => mapping (bytes32 => mapping (bytes32 => bool))) acl;

    function canCall(
        address src_, address dst_, bytes4 sig
    ) public view returns (bool) {
        bytes32 src = bytes32(bytes20(src_));
        bytes32 dst = bytes32(bytes20(dst_));

        return acl[src][dst][sig]
            || acl[src][dst][ANY]
            || acl[src][ANY][sig]
            || acl[src][ANY][ANY]
            || acl[ANY][dst][sig]
            || acl[ANY][dst][ANY]
            || acl[ANY][ANY][sig]
            || acl[ANY][ANY][ANY];
    }

    function permit(bytes32 src, bytes32 dst, bytes32 sig) public auth {
        acl[src][dst][sig] = true;
        emit LogPermit(src, dst, sig);
    }

    function forbid(bytes32 src, bytes32 dst, bytes32 sig) public auth {
        acl[src][dst][sig] = false;
        emit LogForbid(src, dst, sig);
    }

    function permit(address src, address dst, bytes32 sig) public {
        permit(bytes32(bytes20(src)), bytes32(bytes20(dst)), sig);
    }
    function forbid(address src, address dst, bytes32 sig) public {
        forbid(bytes32(bytes20(src)), bytes32(bytes20(dst)), sig);
    }

}

contract DSGuardFactory {
    mapping (address => bool)  public  isGuard;

    function newGuard() public returns (DSGuard guard) {
        guard = new DSGuard();
        guard.setOwner(msg.sender);
        isGuard[address(guard)] = true;
    }
}